Table. Outbreaks and cases of Escherichia coli O157 infection by transmission route, 1982–2002.

Transmission route	Outbreaks			Outbreak size	Cases
	n	Total %	Foodborne %	Median (range)	n	Total %	Foodborne %
Ground beef	75	21	41	8 (2–732)	1,760	20	33
Unknown food vehicle	42	12	23	8 (2–86)	646	8	12
Produce	38	11	21	20 (2–736)	1,794	21	34
Other beef	11	3	6	17 (2–323)	563	7	11
Other food vehicle	10	3	5	15 (2–47)	206	2	4
Dairy product	7	2	4	8 (2–202)	300	3	6
Subtotal, foodborne	183	52		11 (2–736)	5,269	61
Unknown transmission route	74	21		4 (2–140)	812	9
Person-to-person	50	14		7 (2–63)	651	8
Recreational water	21	6		8 (2–45)	280	3
Animal contact	11	3		5 (2–111)	319	4
Drinking water	10	3		26 (2–781)	1,265	15
Laboratory-related	1	<1		2	2	<1
Subtotal, other routes	167	48		5 (2–781)	3,329	39
Total	350				8,598